Rajon Rondo of the Boston Celtics is defended by Chris Bosh of the Toronto Raptors during Sunday's game. (Chris Young/Canadian Press)

The Boston Celtics scored the first 10 points of the game on Sunday afternoon and rarely looked back in a 118-103 victory over the Toronto Raptors.

Ray Allen had 21 points to lead the way offensively for Boston (13-2), which had seven players finish in double digits.

Chris Bosh finished with 24 points and six rebounds for Toronto (6-7), which has a losing record for the first time this season. The Raptors have allowed more than 100 points in all but one of their defeats.

Bosh appeared frustrated with his team's play for much of the second half.

"I don't know the situation here or what he's going through, but tonight, he looked pretty frustrated," Celtics all-star forward Kevin Garnett said of Bosh after the game. "When you're a good player and trying to be better, trying to be one of the premiers in this league, trying to set your mark, you want the help around you.

"He has to make a decision on whether he wants to be here."

When he finally appeared from the shower following the game, Bosh insisted he had already put the loss behind him.

"It doesn't matter what happened on the court. We tried. They kicked our butts. Look forward to Wednesday," he said. "I've been in worse situations. I'm sure guys on this team have been there, too. We're not in a bad spot. We just have to pick it up and continue to push each other and just get it right.

"You guys keep using 'frustrating' and everything. It's over. Do we want other teams to shoot like that? No. Do we want to do a better job on defence? Yes. But it happens."

Raptors coach Sam Mitchell said he understands Bosh's situation.

"Chris and I have been here together for a while, and we have been here through tough times," he said. "You have to remember we are 6-7, there is a lot of basketball to play. It's 13 games into the season and everyone is frustrated, especially coming off a tough loss to Jersey and having a bad performance the way we did today.

"Chris and I have talked about it, and he is frustrated, but we have been through tougher times than this."

Jermaine O'Neal gave it a go on Sunday after crashing to the floor with a left knee injury two nights earlier against New Jersey. He fell awkwardly again in the second quarter of the Boston game and departed within 20 minutes of the start, not to return.

O'Neal had six points and two rebounds before he left. He was pulled down under the basket on a flagrant foul by Sean Williams of the Nets on Friday.

The centre missed 40 games last season due to knee problems while with Indiana before coming over to the Raptors in an off-season trade.

Toronto's defence proved shoddy on Sunday, allowing the Celtics to shoot at a 62 per cent clip. Toronto shot 44 per cent, a number that enhanced in the fourth quarter when the outcome was already not in question.

Garnett, Tony Allen and Rajan Rondo each had 15 points for the Celtics, winners of five straight.

Anthony Parker, Jose Calderon and Andrea Bargnani all had 14 for the Raptors.

Toronto is in the midst of a four-game homestand. The Raptors play Charlotte on Wednesday and Atlanta two nights later.

Big early lead

Boston converted a pair of turnovers soon after the opening tip for points. Paul Pierce then drained a three-pointer and Kendrick Perkins drove a dunk home for a 10-0 lead.

The lead was extended to 22-6 when Rondo made a layup and soon after hit a pair of free throws.

The Raptors clawed back, with Bargnani's longball the highlight to get the team within eight. Garnett hit a three, however, to give Boston a 32-20 lead after one quarter.

Bosh and Jamario Moon made jumpers at the beginning of the second, and when Toronto's Kris Humphries strung together six points to make the score 36-30 Boston, Celtics coach Doc Rivers called a timeout.

It worked. Boston began to assert itself defensively, forcing Toronto shooters into a cold spell. Reserve Eddie House converted a trey as the visitors extended their lead to 18 points.

Moon made two free throws before the half for a 59-49 score at the break.

That was about as competitive as it got, with Allen hitting a pair of three-pointers at the start of the second half to set the tone.

Perkins got too enthusiastic with a dunk that made the score 87-64, incurring a technical foul for his boisterous reaction.

Bosh hit a three-pointer to temporarily get the margin back in the teens, but it was back up to 22 at the end of three.

The Raptors came out with vigour in the fourth. Bargnani hit a three-pointer, and sub Roko Ukic made consecutive steals and baskets for an 8-0 run.

The lead was too big, however, with Toronto only getting within a dozen at one point.

Boston held a 36-31 rebound advantage.

In the teams' previous tilt, the Celtics won at home over Toronto on Nov. 10, coming from behind for a 94-87 result.

With files from the Canadian Press